There is a worldwide pandemic of diabetes in humans. In addition to diabetes, more than one in every three adults in the United States, an estimated 86 million people have metabolic syndrome, also called prediabetes. An estimated 440 million people in the world will possibly have diabetes by 2030, and there is a dire need to stem concurrent pandemics of metabolic syndrome, type 1 diabetes and type 2 diabetes.
In human subjects, high serum ferritin and iron overload have also been associated with metabolic syndrome, type 2 diabetes, and type 1 diabetes. While iron overload is most commonly associated with a mutation in the HFE gene resulting in C282Y substitutions, there is increasing recognition of high serum ferritin that is not associated with known genetic mutations. Ferritin is a measurement of total iron body stores. High ferritin in the blood (i.e. hyperferritinemia) and associated iron overload have been associated with metabolic syndrome (prediabetes), type 2 diabetes and type 1 diabetes in humans. Until now, serum ferritin has not been routinely tested in human subjects, but the few screening studies known in the prior art have demonstrated that a surprisingly high percent (28% and 12%) of healthy elderly men and women in the United States have hyperferritinemia. It is unknown precisely how high ferritin increases the risk of diabetes, but proposed mechanisms include direct injury to the liver and pancreas from excessive deposition or indirect injury from increased oxidative radicals.
Like human subjects, bottlenose dolphin (Tursiops truncatus) subjects can also be susceptible to metabolic syndrome, including high insulin, glucose, triglycerides, fatty liver disease, and iron overload. Iron overload in dolphins, involving excessive iron deposition primarily in the liver's Kupffer cells, can be progressive with age and can be associated with elevated insulin, lipids, and liver enzymes. This disease is associated with neither mutations in the HFE gene nor increases in studied acute phase proteins. Similar to humans, iron overload in dolphins is treated with phlebotomy, and repeated treatments are needed throughout life due to returning elevations of serum ferritin. The underlying causes of iron overload and hyperferritinemia in dolphins are unknown.
Dolphins at the Navy Marine Mammal Program (MMP) are a well-studied dolphin population with regard to metabolic syndrome, and this population has a higher risk of developing metabolic syndrome when compared to wild dolphins, such as wild dolphins living in Sarasota Bay, Fla., for example. When comparing the two populations, neither body mass indices nor stress indices (i.e. cortisol) are risk factors for metabolic syndrome in MMP dolphins. In studies comparing values of blood-based indicators of metabolic syndrome, MMP dolphins have been older than Sarasota Bay dolphins; older age of the MMP dolphin population is further supported by its higher annual survival rates and longer lives compared to wild dolphins, including those living in Sarasota Bay. Proposed risk factors for metabolic syndrome in dolphins can include advanced age, differences in feeding and activity schedules, and differences in dietary fish. It can be hypothesized that differences in dietary fish (and certain fatty acids associated with particular types of fish) can be responsible for differences in the risk of metabolic syndrome and iron overload in dolphins.
In view of the above, it is an object of the present invention to provide a method for detecting protective and risk factors against and for metabolic syndrome and hyperferritinemia in mammal subjects such as dolphins and humans. Another object of the present invention is to provide a method for treating metabolic syndrome and/or hyperferritinemia in mammal subjects, such as dolphins and humans. Still another object of the present invention is to provide a method for detecting metabolic syndrome and/or hyperferritinemia in mammal subjects, such as for dolphins and humans that increases the level of heptadecanoic acid of the subject sera. Yet another object of the present invention is to provide a method for detecting and treating hyperferritinemia without resorting to phlebotomy. Another object of the present invention is to provide a method for detecting and treating metabolic syndrome and/or hyperferritinemia in mammal subjects, such as dolphins and humans that is easy to accomplish in a cost-effective manner.